目的：通过Meta分析系统评价血液中miR-21对胰腺癌的诊断价值。方法：检索多个国内外数据库，收集2017年5月以前公开发表的关于miR-21用于胰腺癌诊断的研究数据，按照纳入标准筛选文献、提取资料和质量评价，然后采用Metadisc 1.4和Stata 14.0软件对纳入研究进行Meta分析。结果：共纳入8篇文献，累计261例胰腺癌患者和242例对照。Meta分析结果显示，循环miR-21诊断胰腺癌的合并敏感度为0.76（95% CI=0.71~0.81），合并特异度为0.76（95% CI=0.70~0.81），合并阳性似然比为3.17（95% CI=2.24~4.47），合并阴性似然比为0.26（95% CI=0.15~0.45），合并诊断比值比为13.17（95% CI=6.78~25.58）。综合受试者工作特征曲线下面积（AUC）为0.8518。亚组分析显示，血清和血浆亚组的AUC均为0.8513；健康人群对照亚组的诊断准确性优于健康人群+胰腺良性疾患对照亚组（AUC：0.876 vs. 0.72，P<0.05）。诊断性试验Deek漏斗图显示不存在发表偏倚，敏感性分析显示Meta分析结果并未过分依赖于某个研究，结论稳定。结论：循环miR-21用于胰腺癌诊断具有一定的价值。
Meta-analysis of value of circulating miR-21 in diagnosis of pancreatic cancer
Objective: To systematically evaluate the value of circulating miR-21 in diagnosis of pancreatic cancer through Meta-analysis. Methods: The studying data concerning using circulating miR-21 in diagnosis of pancreatic cancer published before May 2017 were collected through searching several national and international databases. After screening for inclusion criteria, data extraction and quality assessment, Meta-analysis was performed by using MetaDisc 1.4 and Stata 14.0 software. Results: A total of 8 studies were included with 261 pancreatic cancer patients and 242 control subjects. The results of Meta-analysis showed that the pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio of circulating miR-21 for diagnosis of pancreatic cancer was 0.76 (95% CI=0.71–0.81), 0.76 (95% CI=0.70–0.81), 3.17 (95% CI=2.24–4.47) and 0.26 (95% CI=0.15–0.45), respectively. The diagnostic odds ratio value was 13.17 (95% CI=6.78–25.58), and the area under the summary receiver operator characteristic curve (AUC) was 0.8518. Subgroup analysis showed that the serum and plasma subgroups had a same AUC value of 0.8513, and the diagnostic accuracy of the healthy population control subgroup was better than that of the health population plus benign pancreatic disease patients control subgroup (AUC: 0.876 vs. 0.72, P<0.05). The Deek’s funnel plot for the diagnostic test showed that there was no publication bias, and the sensitivity analysis showed that the results of this analysis were not strongly dependent on any single study and that the conclusions were stable. Conclusion: Circulating miR-21 has certain value in diagnosis of pancreatic cancer.